mcallistee



(No Model.)

G. W. MGALLISTER.

STEAM GENERATOR.

No. 287,452. Patented Oct. 30, 1888.

UNITED; STATES GUY W. MCALLISTER, OF BOSTON, MASSACHUSETTS, ASSIGNOR TOHIMSELF,

`EDVARD L. YORK, AND ALDIS L. WAITE, OF SAME PLAGE.

STEAM-GENERATOR.

SPECIFICATION forming part of Letters Patent No.`287,452, dated October30, 1883.

Application filed May 5, 1883. (No model() I I To (all whom t mayconcern:

Be it known that I, GUY W. McALLIsTnR, of Boston, in the county ofSuffolk, State of Massachusetts, have invented a certain new 5 anduseful Improvement in Steam-Generators, of which the following is adescription sufficiently full, clear, and exact to enable any personskilled in the art or science to'which said invention appertains-to makeand use the same, reference being had to the accompanying drawing,forming a part of this specication, in which the figure is a sideelevation, a portion of the body, fire-pot, and casing being representedas removed or shown in vertical longitudinal section.

My invention relates to that class of steamgenerators in which the waterto be converted into'steam is passed through a coil or helix disposed inthe fire-pot or combustion-chamber; and it consists in a novelconstruction and arrangement of the parts, as hereinafter more fully setforth and claimed, by which a more effective article of this characteris prof duced than is now in ordinary use.

The nature and operation of the improvement will be readily understoodby all conversant with such matters from the following explanation, itsextreme simplicity rendering an elaborate description unnecessary.

In the drawing, A represents the body of the generator, and B the casingor jacket. The body is cylindrical in form, and provided with the bottomC and head D. Disposed on the head there is a hollowcone-shapedforam'inous top or cap, E, opening at its apex into the funnel F, thecap being connected n with the body by a series of ports or ilueholes,a. The jacket is preferably composed of zinc, galvanized iron, or someother good non-conductor of heat, and is attached at x to the top of thecap E, an air-space, d, being left between the jacket and body, withinletopenings f around the bottom.

A globular steam-dome, G, is disposed in i 4 5 the cap E, beingsupported in the head D, and

projecting downwardly a short distance into the body A. This dome isconnected, by means of the vertically-arranged pipes H I, with theannular water-chamber J in the lower part 5o of the generator, thechamber protruding upwardly through the grate of the fire-pot K, whichrests on the brackets or ledges m.

An induction-pipe, L, for supplying water, enters the generator oppositethe chamber J, and passes upwardly to near its center, being there bentinwardly over the fire-pot, and ascending to the top of the closedvertically-arranged cylindrical' heating-chamber M, where it is coileddownwardly around said chamber, forming the helix L', and entering thechamber at z'.

Connected with the top of the chamber M there is a pipe, N, which isformed into a coil or helix, O, around the pipes I H, below the chamberM. A pipe, I), connected with the chamber J, is also formed into a coilor helix, Q, around the pipes I H, abovelthe chamber J, the helices O Qbeing connected by the short vertical pipe R. A blow-off pipe, j,provided with the stopcock h, is connected with the chamber J, and'thereis a test or pet cock, 1, connected by the pipe r with the chamber M. Aglass gagetube, S, is arranged and around this pipe, within thecylinder, a

section of the induction-pipe L is coiled, as shown. Leading from thedome G there is also an eduction steam-pipe, 20, provided with arelief-valve, 26, and with a pipe, 2l,

connecting with the indicator or steamgage 22. j

-In the use of my improvement, a fire is started in the ordinary manner,in the fire-pot K, and water let into the apparatus through the pipe L,the stop-cock 28 in the pipe V being open. On entering the generator thewater is first carried to the upper part of the body A, where it passesinto the chamber M through the surrounding coil L. This chamber beingover the iire-pot and in the direct path of the escaping hot air, gases,and products of combustion, the heat therefrom, Whichwould otherwise belargely wasted, is utilized to its greatest IOO extent in heating thewater and converting it into steam. From the chamber Mthe steam andwater pass downwardly through the helix O, pipe R, helix Q, and pipePinto the chamber J, the water being converted into steam on itspassage, and the steam superheated in sai d lastnamed chamber, fromwhich it rises through the pipes I H into the dome G, where `itstemperature is maintained by the hot air and products of combustionpassing through the ports or ues a, which open through the head D injuxtaposition to the dome.` The feed-water is heated before it entersthe generator, on its passage through the coil in the cylinder W, byradiation from the pipe V, thereby utilizing the heat of the steam afterit leaves the generator and reducing its temperature, whereby it isbetter adapted for use as a motor.

The jacket B is designed to prevent the waste of heat radiating from thebody A-, the air,

A which enters at f, being heated, and rising through the cap E andimpinging on the dome G, thereby not only assisting to maintain thetemperature of the steam in saidv dome, but aiding to keep up the draftthrough the funnel F.

The superposed helix O, being detachably connected with the helix Q,'maybe readily removedfor repairs, when necessary, without disturbing thelatter helix, and vice versa.

The body A is designed to be connected by nutsand bolts and cemented orair-tight joints to the head D and bottom C, but in such a manner as tobe readily detachable therefrom. A check-valve, 24, is provided toprevent the refiux of water through the pipe L, and also proper shut-offcocks, 25, at the upper and lower ends of the gage S. If, on account ofa low fire or any other reason, the water is not fully converted intosteam in the chamber M and helices O Q, its evaporation will becompleted in the chamber J and pipes I H, the

gage S indicating the amount of water in the superheating-chamber andsaid pipes. The

Having thus explained my invention, what I claim -is-; A

1. The improved steamgenerator herein described, the same consisting ofthe body A, provided'with the jacket B, head' D,l bottom C. fire-pot K,cap E, and funnel F, the induction-pipe L, chamber M, helices L/,O Q,chamber J, pipes I H, dome G, relieivalve 26, and eduetion-pipe V,constructed, combined, and arranged to operate substantially as setforth.

2. Inasteam-generator, the dome G, in combination with the head D, pipesI H V, and cap E, constructed and arranged to operate substantially asshown land described.

3. The combination of an exterior casing or combustion chamber, a closechamber, M, within said combustion-chamber, a spirallycoiled pipe, L',surrounding said close chamber, the upper end of said coil beingconnected t0 va water-supply pipe passing through thecombustion-chamber, the lower end thereof 'entering the bottom of saidclose chamber,

an eduction-pipe, N, leading from the top of said close chamber, ,and acoil below said close chamber connected with said eductionpipe,substantially as described.

4. In a steam-generator, the gage S,in combination with the superheatingsteam-charm ber J and pipes H U rI L, substantially as set forth.

GUY W. MCALLISTER.

Vitnesses:

C. A. SHAW, J. W. VAUGHN.i

